Accessories are popular for adding functionality to vehicles, such as bicycles, scooters, and motorcycles. With respect to bicycles, accessories include bike racks, water bottle holders, computers, lights, mirrors, and electric motors, among other things. These accessories typically must be physically attached to the bicycle in order to work correctly and, in many cases, the position of the accessory should be fixed relative to the bicycle in a way that avoids shaking, vibration, and slippage between the bicycle and the accessory. For example, a bike rack may be attached to the forks of a bicycle, a mirror may be attached to the handlebars, and a water bottle holder may be attached to the frame. In each of these three examples, it is desirable to attach the accessory securely to the bicycle in a way that minimizes relative shaking, vibration, and slippage.
Manufacturers of vehicle accessories typically want their product(s) to work with as many vehicles as possible. A problem is that vehicles come in many different types, styles, and sizes, which makes it difficult to create a uniform method of securely attaching accessories to them. For example, bicycle tubing in the frame, forks, and handlebars varies widely in size and shape. Existing fastening systems are unable to securely attach accessories across a wide-range of tubing sizes and shapes without permanently modifying the bicycle.
It is possible to permanently attach an accessory to a bicycle, for example, by drilling holes in the tubing and using screws to mount the accessory. But this requires creating permanent holes in the tubing, which may impair structural strength, reduce the bicycle's value, and also makes it difficult to change accessories later. Welding or gluing an accessory to the bicycle creates the same type of problems by permanently modifying the bicycle and making it difficult to change accessories.
An alternative to permanently attaching an accessory is to use a removable fastening mechanism around the tubing, such as a clamp. Clamps have the advantages that they may be attached and removed from a bicycle (or other vehicle) without damaging it, and clamps may be positioned at different points on the tubing, depending on the type of accessory and the rider's preference. However, existing clamps have problems fitting securely on tubing of various sizes and shapes while bearing a load. A clamp that fits securely on one size of tubing will often not fit securely on another size of tubing. This problem is particularly severe when mounting heavy or load-bearing accessories, such as electric motors or bike racks, because the weight places a strain on the attachment point(s) of the clamp, which may cause the clamp to vibrate, slip, and/or bend; it also places a strain on the tubing, which may mar the paint finish or even dent the tubing.
Clamps, called “band clamps”, have a flexible body and narrow width that allows them to fit on multiple sizes of tubing. However, the flexibility and narrowness makes these clamps unsuitable for bearing a substantial load, because there is not enough grip between the clamp and the tubing to prevent slippage and there is insufficient stiffness at the attachment point(s) to prevent vibration, among other problems. Other clamps with solid bodies exist for securely fitting onto one size and shape of tubing. However, existing solid clamps cannot fit securely onto a wide-range of shapes and sizes of tubing, because the fixed cross-section properly fits only one size and shape. Moreover, no existing clamps—flexible or solid—have the ability to fit securely onto a tapered tube while bearing a load. Tapering of the tube causes existing clamps to slide in the direction of reduced tube diameter, this problem becomes more severe as the load increases.
Accordingly, there is a need in the art for a removable fastening mechanism that combines sufficient stiffness to bear a load with the ability to fit securely on a wide-range of sizes and shapes of tubing, including tapered tubing.